Hearts forward Steven Naismith has admitted he regrets his angry reaction to Jonny Hayes in the 1-0 win over Celtic earlier in August.
But Naismith says the Scottish FA made the "sensible" decision not to charge him or Scott Brown for separate off the ball incidents in the game.
Naismith kicked out at Hayes then angrily stood over him after a challenge from the Celtic winger.
"I was totally wrong in my reaction," Naismith told BBC Scotland.
Naismith was not booked for the incident, though did pick up a yellow card in the game for a challenge on Celtic defender Jozo Simunovic.
Both Naismith and Celtic captain Brown were later cited by the SFA compliance officer, with Brown also appearing to elbow the former Scotland forward, but the decision was made to take no action.
"Looking back on it, after Jonny went down, I had the red mist," Naismith said on Sportsound. "When I did my first knee injury it was a pretty similar tackle and that was what was going through my head.
"Definitely [I regret it]. And even after it I was saying to Jonny during the game, 'are you alright, sorry about that'. I didn't realise he was that injured, it was more just a reaction to getting scythed down."
The 31-year-old says he "loves" playing against Celtic captain Brown, and had no problem with the challenge on him.
Naismith said: "I saw on TV a referee was saying 'there's no malice in it' and that's exactly what it was. It was me raging at the tackle and a natural reaction.
"And Broony's was the same, it's not enough to be a red card, and I think it was sensible the reaction that came out of the SFA."